1. Field of the Invention
The present invention relates to a navigation system of a motor vehicle having an input unit, a position-determining unit, a central processor unit for calculating a route between a first and a second location by reference to map data, which contains information for determining a predicted fuel consumption for the route, and an output unit for outputting travel instructions which are matched to the current position of the vehicle. The present invention also relates to a method for determining a route.
2. Description of the Related Art
A navigation system and a method for determining a route are known, for example, from DE 196 05 458 C1. In this known navigation system, a destination is first selected by the driver and the current position of the vehicle is determined by satellite navigation signals. The navigation system then calculates a plurality of routes from the current position of the vehicle to the destination. In the process, the fuel which is predicted to be required is calculated for each of the routes. The calculation of the fuel consumption is carried out on the basis of changes in altitude on the respective routes. The topological properties which are required for this are stored together with the road map data. A preferred route is selected from the various routes, the preferred route having the lowest fuel consumption. The preferred route is finally output. A disadvantage of this known method is that the fuel consumption is the only criterion for the selection of a route.
Furthermore, U.S. Pat. No. 5,315,295 and DE 101 29 149 A1 disclose feeding setpoint values to a travel speed controller from a navigation system.